//
// experimental/detail/channel_payload.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef ASIO_EXPERIMENTAL_DETAIL_CHANNEL_PAYLOAD_HPP
#define ASIO_EXPERIMENTAL_DETAIL_CHANNEL_PAYLOAD_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include "asio/detail/config.hpp"
#include <variant>
#include "asio/detail/type_traits.hpp"
#include "asio/experimental/detail/channel_message.hpp"

#include "asio/detail/push_options.hpp"

namespace asio {
    namespace experimental {
        namespace detail {

            template<typename... Signatures>
            class channel_payload {
            public:
                template<typename Signature>
                channel_payload (ASIO_MOVE_ARG(channel_message <Signature>)

                m)
                :

                message_ (ASIO_MOVE_CAST(channel_message <Signature>)(m)) {
                }

                template<typename Handler>
                void receive(Handler &handler) {
                    std::visit(
                            [&](auto &message) {
                                message.receive(handler);
                            }, message_);
                }

            private:
                std::variant<channel_message < Signatures>...>
                message_;
            };

            template<typename R>
            class channel_payload<R()> {
            public:
                explicit channel_payload(channel_message<R()>) {
                }

                template<typename Handler>
                void receive(Handler &handler) {
                    ASIO_MOVE_OR_LVALUE(Handler)(handler)();
                }
            };

            template<typename Signature>
            class channel_payload<Signature> {
            public:
                channel_payload(ASIO_MOVE_ARG(channel_message<Signature>)

                m)
                :

                message_ (ASIO_MOVE_CAST(channel_message <Signature>)(m)) {
                }

                template<typename Handler>
                void receive(Handler &handler) {
                    message_.receive(handler);
                }

            private:
                channel_message <Signature> message_;
            };

        } // namespace detail
    } // namespace experimental
} // namespace asio

#include "asio/detail/pop_options.hpp"

#endif // ASIO_EXPERIMENTAL_DETAIL_CHANNEL_PAYLOAD_HPP
